RUARIDH JACKSON is determined not to let a rib knock stop him from filling his call of duty at No.10 for Scotland in this season's RBS Six Nations Championship.

The Dark Blues will face England in the Calcutta Cup in the tournament opener at Twickenham on Saturday week. Interim head coach Scott Johnson indicating that his preferred half-back partnership will see the Glasgow Warriors stand-off in harness with Edinburgh skipper Greig Laidlaw at scrum-half.

Concerns over Jackson's fitness began to appear at Scotstoun on Saturday after the Warrior suffered a second blow to an existing rib injury in the Heineken Cup finale with Northampton.

But the 24-year-old has returned to training and is desperate to start against the Auld Enemy.

He said: "The England game is the one that every Scotsman dreams of playing in.

"Our record has not been good down there and I think the last time we won at Twickenham was way back in 1983.

"But of late it has been tight. I played two years back when I slotted a drop goal and we lost late on by 22-16.

"We will be underdogs on Saturday week, even more so when you consider that England beat the world champions New Zealand the last time they played at home, but that suits us fine.

"I am just desperate to play and hopefully everything is looking good now that I have been back in training for a couple of days."

While Jackson admits to a certain amount of frustration at the fact he has only just re-established himself as the starting 10 at Warriors, he also accepts that his troubles in doing so have been partly down to injury and also the competition he faces from Duncan Weir and Scott Wight.

Jacko said: "I've started five out of the last six games for Glasgow and I have felt that I am starting to find form.

"Against Northampton I felt like my goal kicking was good and that I was managing the game well only to take another knock to the rib injury.

"With that and the intensity of the competition at Warriors, you really do have to produce your best every time. It's ideal preparation for Scotland."